Cooling systems for transformers

ABSTRACT

A cooling system for electric transformers in which the individual radiators are connected with upper and lower main headers at diagonally opposite corners of the radiators.

United States Patent Inventor Ronald Rutherford Sunderland, England App]. No. 854,128 Filed Aug. 29, 1969 Patented Oct. 5, 1971 Assignee Washington Engineering Limited Washington, England Aug. 30, 1968 Great Britain Priority COOLING SYSTEMS FOR TRANSFORMERS 4 Claims, 7 Drawing Figs.

Int. Cl F28b 7/00 [50] Field oiSearch 336/57,58, 61; 165/106, 107.46, 77. 78, 170, 120; 285/325 [56] References Cited UNITED STATES PATENTS 7 1,800,163 4/1931 Thompson 165/47 X 2,190,584 2/1940 Feldmeier et a1. 165/77 X 2,195,013 3/1940 Rastetter et al 285/325 X 3,372,738 3/1968 Janetal 165/47 Primary ExaminerFrederick L. Matteson Assistant Examiner-Theophil W. Streule Attorney-Wenderoth, Lind & Ponack ABSTRACT: A cooling system for electric transformers in which the individual radiators are connected with upper and lower main headers at diagonally opposite comers of the radiators PATENTED um 51971 SHEET 1 UF 3 w I I 7 A Q :J. F

VII

RONALD RUTHERFORD, Inventor nd/MM Attorneys PATENTEUUET 51971 1610327 11 C I I RONALD RUTHERFORD I nvcnto I y Malia/ m Attorneys PATENTEDUCT SIHYI 3,610,327

sum 3 OF 3 RONALD RUTHERFORD, Inventor mull/1% 1 1 Attorneys COOLING SYSTEMS FOR TRANSFORMERS This invention relates to cooling systems for electric transformers of the kind in which the transformer oil is circulated by gravity or by means of a pump through one or more radiators. These radiators normally comprise a plurality of sections each formed from two pressed metal half sections and each extending at right angles to top and bottom headers.

A typical cooling system will comprise a bank of such radiators connected with upper and lower main frame headers, the individual radiators being cantilevered outwards from, and on both sides of, the main frame headers by their own individual headers.

This conventional arrangement has a number of disadvantages. The combined weight of the radiator and its oil filling tends to cause it to sag. This in turn imposes undesirable loads on the flanges of the radiator headers and the studs by which these flanges and thus the complete radiator is secured to the main headers. Furthermore the tendency to tilt of the flange relative to the main header may reduce the compression on the upper part of the intervening gasket to the extent that oil leaks occur. A further disadvantage of this arrangement is that the individual radiators tend to vibrate relative to the main frame headers both when the transformer is in operation and the radiators are full of oil and when the radiators are empty and the complete bank is being transported to site. This leads to stresses being set up in the welds between the sections and the headers and damage due to metal fatigue and weld failure occurs.

These various disadvantages are obviated by the improved arrangement of this invention in which the two main frame headers are arranged in spaced vertical and horizontal planes, the top header of each radiator is connected at one end with the upper main header and the bottom header of each radiator is connected at the corresponding other end with the lower main header whereby each radiator is supported at diagonally opposite comers.

Such an arrangement has been found to reduce both the extent of vibration during normal operation and the stresses set up during transportation. It also allows each radiator to be made considerably longer since there is no danger of its sagging as in the conventional arrangement.

A greater length of radiator is also practicable because since the liquid flow in each radiator is between top and bottom opposite comers a more even distribution of liquid within the radiator occurs. Accordingly a greater length of radiator can be used efficiently than is the case in the conventional arrangement where the liquid flow is between top and bottom corners of the same side of the radiator.

In order that the invention may be clearly understood it will now be described with reference to the accompanying drawings, in which:

FIGS. 1 and 2 are end and side elevations respectively of a known cooling system,

FIGS. 3 and 4 are end and side elevations respectively of a cooling system in accordance with the invention,

FIGS. 5 and 6 are an end elevation and a side elevation of a header coupling flange, and

FIG. 7 is a side elevation showing the connection of a coupling flange to a main header.

Referring firstly to the prior art arrangement illustrated in FIGS. 1 and 2, there are shown two vertically spaced main headers l and 2 with which are connected a plurality of radiators 3, 4 and 5. Each radiator comprises a plurality of sections 6, conventionally fonned of pressed sheet metal half sections welded together round the periphery, which are connected with and arranged at right angles to top and bottom headers 7 and 8. At corresponding one ends these top and bottom headers are provided with mounting flanges 9 which are drilled to receive threaded studs carried on the main headers l and 2. When so mounted the individual radiators are cantilevered outwards from, and on both sides of, the main headers 1 and 2 by their top and bottom headers 7 and 8 and are not otherwise supported. The illustrated system is completed by pipes 10 and 11 leading from the main headers l and 2 to the transformer tank, not s own, a pump 12 in the pipe 11 for circulating cooling oil through the radiators, and fans 13 for increasing the flow of air round the radiator system.

In FIGS. 3 and 4, in which the same numerals are used to denote similar parts, a cooling system in accordance with the invention is illustrated. In these figures it will be seen that the main headers 1 and 2 are arranged in spaced vertical and horizontal planes so that they do not lie one above the other as in the system of FIGS. 1 and 2. Moreover while one end 14 of the top header 7 is connected with the upper main header 1 it is the corresponding other end 15 of the bottom header 8 that is connected with the lower main header 2, with the result that the radiators are supported at diagonally opposite corners.

The upper and lower main headers are supported by frame members 16, 17 and 18, 19 respectively. The frame members 16, 17 are connected by a crossmember 20 and to this member is secured the end 21 of the bottom header 8 opposite to the end which is connected to the lower main header 2. In this manner additional support is provided for each radiator.

The invention also includes an improved arrangement for attaching the radiators 3, 4, 5 to the main headers l and 2. In the conventional system illustrated in FIGS. 1 and 2 each radiator has to be moved laterally of the main headers so as to separate its connecting flanges 9 from the holding studs mounted on the main headers. In the improved arrangement of this invention, the two mounting flanges 9 of a radiator are each formed, as shown It FIGS. 5 and 6, with slots 21 extending upwards from their periphery so that the flanges can be mounted on suitably positioned studs 22 by a downwards movement of the whole radiator. In such an arrangement a radiator may be removed from the bank merely by releasing the holding nuts and lifting it vertically.

Such arrangement also permits shear loads to be removed from the studs since, as shown in FIG. 7, a plate 23 may be secured on the main header in such a position that the lower edge of the flange 9 rests on the plate 23 once the radiator is in position.

Iclaim:

1. Cooling system for electric transformers comprising a plurality of radiators each connected with and supported by upper and lower main headers, each radiator comprising top and bottom headers and a plurality of sections connected therebetween and extending at right angles thereto, and the top and bottom headers of each radiator being connected respectively with the upper and lower main headers, wherein the two main headers are arranged in spaced vertical and horizontal planes, the top header of each radiator is connected at one end with the upper main header and the bottom header of each radiator is connected at the corresponding other end with the lower main header whereby each radiator is supported at diagonally opposite corners.

2. Cooling system as claimed in claim 1, wherein each main header is supported on a frame and the end of each bottom radiator header opposite to the end connected with the lower main header is secured with the frame supporting the upper main header.

3. Cooling system as claimed in claim 1 or claim 2, wherein the top and bottom headers of each radiator are provided with a flange for attachment to the main headers and each flange is formed with slots extending upwards from the periphery and positioned to receive studs extending from the main header.

4. Cooling system as claimed in claim 3, wherein each main header is provided with projections which engage and form a seat for the periphery of the flange of a top header to be connected thereto. 

1. Cooling system for electric transformers comprising a plurality of radiators each connected with and supported by upper and lower main headers, each radiator comprising top and bottom headers and a plurality of sections connected therebetween and extending at right angles thereto, and the top and bottom headers of each radiator being connected respectively with the upper and lower main headers, wherein the two main headers are arranged in spaced vertical and horizontal planes, the top header of each radiator is connected at one end with the upper main header and the bottom header of each radiator is connected at the corresponding other end with the lower main header whereby each radiator is supported at diagonally opposite corners.
 2. Cooling system as claimed in claim 1, wherein each main header is supported on a frame and the end of each bottom radiator header opposite to the end connected wIth the lower main header is secured with the frame supporting the upper main header.
 3. Cooling system as claimed in claim 1 or claim 2, wherein the top and bottom headers of each radiator are provided with a flange for attachment to the main headers and each flange is formed with slots extending upwards from the periphery and positioned to receive studs extending from the main header.
 4. Cooling system as claimed in claim 3, wherein each main header is provided with projections which engage and form a seat for the periphery of the flange of a top header to be connected thereto. 